1. Field of the Invention
The present invention relates to a tape printing apparatus that enables a user to input an image using an input device such as an input pen and a graphic input panel, a mouse or a joystick while simultaneously viewing the image on a display screen. The device may also be capable of printing the input image on an elongated recording medium to make a pictorial tape label. In particular, the invention relates to a tape printing apparatus capable of automatically and continuously switching the display of the display screen to different portions of an image in response to the position of the input device on the graphic input panel so that an image which is too large to be entirely displayed on the display screen may be drawn and edited smoothly.
2. Description of the Related Art
It is known to input graphical images into a general purpose computer using an input device comprised of a graphic input panel and an input pen. Such devices allow a user to indicate particular positions on the input panel with the input pen to input an image. Alternately, an image may be input using a mouse, a joystick, a trackball, cursor keys, or other devices for indicating particular positions of an input image.
A display screen connected to the computer usually displays all or a portion of the input image so that the user can verify that the image is correctly entered. A printer may also be connected to the computer to print the input image.
Unfortunately, if the prior art apparatus utilizes a graphic input panel and an input pen, the user must make awkward key operations of Cursor keys when the portion of the image he would like displayed is not within the current display range, or when the screen has scrolled beyond the intended position as a result of key operations. When using such a device, if the user wishes to edit a portion of the image that is not currently displayed on the display screen, the user must scroll the screen using a Cursor-left key or a Cursor-right key.
If a prior art apparatus uses an input device such as a mouse, a joystick, a trackball, or the like as the input device, the input device may also operate to scroll the screen automatically when the cursor goes out of the range of display screen. Although such automatic scrolling is useful for automatically shifting the displayed image, the display may continue to scroll, even after the cursor movement has ceased. Thus, even using a device with automatic scrolling, the user must make awkward operations of the input device, such as moving it in the opposite direction of the scrolling, to stop the scrolling of the display and to bring the intended portion of the image back into the display range. In addition, when the cursor is pushed out of the display range and then brought back into the display range by movements of the input device, the positional relations of the input device and cursor may have varied, and it may be necessary to move the input device again to restore their positional relations. Thus, the user must make repeated awkward operations of the input device to display an intended portion of an image and it is difficult, if not impossible, for the user to display an intended portion of an image correctly in a single action.